1. Technical Field
The present invention relates to a device that judges the likelihood of a collision between a vehicle and a target, a vehicle collision avoidance system for avoiding a collision between the vehicle and the target, and a method for avoiding a collision between the vehicle and the target.
2. Related Art
Conventionally, a technology is known in which an image sensor is mounted in a vehicle. A target that is present ahead of the vehicle is detected using the sensor.
The likelihood of the collision between the vehicle and the target is then judged. For example, in a technology described in Japanese laid-open patent JP-A-2006-99155, an amount of time TTC until a target that is present ahead of the vehicle reaches the vehicle is calculated based on an image captured by the image sensor. When the TTC is a threshold or lower, the likelihood of the collision of the vehicle with the target is determined to be high, and then the target becomes subject to monitoring for an evasive action of the collision.
Ordinarily, if a driver driving a vehicle that is the target or a pedestrian that is the target notices the presence of the vehicle with which there is a risk of collision, the driver or the pedestrian takes action to avoid the collision. Therefore, the likelihood of a collision decreases. On the other hand, if the target does not notice the presence of the vehicle with which there is a risk of collision, the target may not take action to avoid the collision. In that case, the likelihood of a collision increases.
As described above, the likelihood of a collision between a target and a vehicle changes depending on the state of the target. However, in the conventional technology, the likelihood of a collision is uniformly determined to be high if a predetermined condition, such as the distance between the target and the vehicle, is met. Therefore, an issue occurs in that the likelihood of a collision is determined to be high, even ma situation in which the likelihood of a collision between the target and the vehicle is actually low.
Hence, a vehicle collision judging device and a vehicle collision avoidance system being capable of appropriately determining the likelihood of a collision depending on the situation are desired.